Flag of current Queen (8)
I believe the answer is:
streamer
'flag' is the definition.
(streamer is a kind of flag)
'current queen' is the wordplay.
'current' becomes 'stream' ('stream' can be a synonym of 'current').
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'stream'+'er'='STREAMER'
'of' acts as a link.
(Other definitions for streamer that I've seen before include "Long strip used at parties" , "Long 23 ac or ribbon" , "Arrest me carrying floating ribbon" , "Paper ribbon - thin flag" , "Item of bunting" .)